I am wanting to swich to Intel,but dont know anything about the different Intel northbridge options.I only have a need for a single core processor and pci-Xx16 video.Any help would be very greatly appreciated.

dont understand ifyou want single core why intel over amd ? we all know conroes are kicking amds butt however single core performance and cost wise amd is going to be miles better, i suggest a cheap 939mobo, an athlon64 3500 or 3800 and they will oc better and kick any p4 that way you can still use your existing ram etc, maybe get a mobo with both agp and pci, so you can upgrade furter in the future